U.S. patent number 4,040,494 [Application Number 05/613,060] was granted by the patent office on 1977-08-09 for drill director.
This patent grant is currently assigned to Smith International, Inc.. Invention is credited to Jackson M. Kellner.
United States Patent |
4,040,494 |
Kellner |
August 9, 1977 |
**Please see images for:
( Certificate of Correction ) ** |
Drill director
Abstract
The casing of a drill motor axis is provided with a deflection
barrel free to turn to position the barrel relative to the motor to
apply lateral force to the side of the motor directed along any
desired radius. A gravity actuated mercury potentiometer connected
to the barrel provides a barrel orientation responsive electric
transmitter for remote indication of the barrel orientation in the
hole being drilled. A hydraulic stepping motor and meshing teeth
are used to position the barrel azimuthally about the motor axis
with the use of vertical alignment means.
Inventors: |
Kellner; Jackson M. (Midland,
TX) |
Assignee: |
Smith International, Inc.
(Midland, TX)
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Family
ID: |
27079189 |
Appl.
No.: |
05/613,060 |
Filed: |
September 15, 1975 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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584736 |
Jun 9, 1975 |
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505450 |
Sep 13, 1974 |
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419106 |
Nov 26, 1973 |
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Current U.S.
Class: |
175/45; 175/61;
175/73; 175/94; 175/230 |
Current CPC
Class: |
E21B
4/18 (20130101); E21B 7/068 (20130101); E21B
21/16 (20130101); E21B 47/022 (20130101) |
Current International
Class: |
E21B
7/04 (20060101); E21B 7/06 (20060101); E21B
4/00 (20060101); E21B 21/00 (20060101); E21B
21/16 (20060101); E21B 47/022 (20060101); E21B
47/02 (20060101); E21B 4/18 (20060101); E21B
007/04 () |
Field of
Search: |
;175/24,45,61,73-77,79,81,94,230 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Purser; Ernest R.
Assistant Examiner: Favreau; Richard E.
Attorney, Agent or Firm: Robinson; Murray
Parent Case Text
CROSS-REFERENCES TO RELATED APPLICATIONS
This is a continuation-in-part of prior copending application Ser.
No. 584,736, filed June 9, 1975, which is a continuation of prior
application Ser. No. 505,450, filed Sept. 13, 1974, now abandoned
which is a continuation of prior application Ser. No. 419,106,
filed Nov. 26, 1973, now abandoned, and the priority of these three
prior applications is claimed.
Claims
What is claimed as invention is:
1. Drilling apparatus comprising
an in-hole assembly adapted to be run in a hole being made, said
in-hole assembly including,
an in-hole motor having a shaft rotated when the motor is actuated,
said shaft being adapted to rotate a drill bit,
a deflection barrel rotatable about the shaft axis,
positioning means for turning the barrel to a desired azimuthal
position relative to the axis of rotation of the motor shaft and
holding it in that position, said positioning means including a
single hydraulic line for actuation, and
said apparatus further comprising
command means for directing said positioning means through said
single hydraulic line,
said deflection barrel including means extendable from the side
thereof to engage one side of a hole being drilled and means to
push the shaft laterally toward the opposite side of the hole,
said in-hole motor including a housing, said deflection barrel
being connected to said housing and said positioning means turning
said barrel along with said motor housing.
2. Apparatus according to claim 1 wherein said means to push the
shaft laterally includes an annular cuff connected to the inner end
of the barrel and a sub connected to the inner end of the shaft and
antifriction bearing means between said cuff and sub.
3. Apparatus according to claim 1 including a bit connected to said
shaft and torque anchor means connected to said housing.
4. Apparatus according to claim 1 including force applicator means
connected to said housing.
5. Apparatus according to claim 1 wherein said means extendable
from the side of the barrel to engage the side of the hole being
drilled includes a tubular cover inside the barrel to form an
annular pressurable chamber therebetween, piston means radially
extendably and retractably mounted in a window in the barrel
adjacent said chamber.
6. Apparatus according to claim 5 wherein said piston means is
mounted in said window by elastomer means bonded to the piston and
window.
7. Apparatus according to claim 1 including transmitting means
connected to the barrel responsive to the attitude position of the
barrel relative to the axis of the hole being drilled for
transmitting an indication of the attitude position of the barrel
to an out of the hole indicator.
8. Apparatus according to claim 7 wherein said transmitting means
is a mercury potentiometer connectible to an out-of-the-hole
indicator of the Wheatstone bridge type, said potentiometer to form
part of the circuit of said bridge.
9. Apparatus according to claim 1 wherein said positioning means
includes a hydraulic stepping motor and detection means for
determining when said barrel reaches a known position.
10. Apparatus according to claim 9 wherein said command means
includes indicator means for indicating the detection by said
detection means of said barrel reaching said known position.
11. Drilling apparatus according to claim 3 comprising
an in-hole force applicator;
said in-hole assembly connected to said applicator.
12. Drilling apparatus according to claim 11:
actuation means for moving said positioning means including a
single hyraulic line.
13. Deflection apparatus of claim 12, comprising:
means detecting a known position of the apparatus through the same
single line.
14. Apparatus according to claim 12 further including rate of
change limiting means for limiting the amount of deflection of said
drill bit.
15. Apparatus according to claim 14 wherein said rate of change
limiting means is nonrotatable.
16. Drilling apparatus adapted to be run in a hole being made, said
apparatus comprising:
an in-hole motor including a housing and having a shaft rotated
relative to said housing when the motor is actuated, said shaft
being adapted to rotate a drill bit when said motor is actuated and
said housing is held against rotation,
a deflection barrel connected to said motor housing,
said deflection barrel including means extendable from the side
thereof to engage one side of a hole being drilled and means to
push the shaft laterally toward the opposite side of the hole,
shaft means to apply force to said motor housing and take counter
torque thereof when it is desired to rotate said drill bit,
connection means connecting said shaft means to said motor housing
to prevent relative axial motion thereof and to permit relative
rotation thereof in one direction for positioning of said
deflection barrel and to prevent relative rotation thereof in the
opposite direction as required to take counter torque when it is
desired to rotate said drill bit; and
positioning means for turning the barrel to a desired azimuthal
position relative to the axis of rotation of the motor shaft and
holding it in that position.
17. Drilling apparatus according to claim 16,
said connection means including a thrust bearing and an overrunning
clutch.
18. Apparatus of claim 16, comprising:
orienting means located in the hole for turning the deflection
barrel about such shaft axis;
said one hydraulic line for transmitting commands to said
positioning means.
19. Apparatus according to claim 16 wherein there is further
included:
detection means for detecting a known position of said deflection
barrel and transmitting such detection through said one hydraulic
line.
Description
BACKGROUND OF THE INVENTION
1. Field of Invention
This invention pertains to earth boring and more particularly to
drill directing apparatus.
2. Description of Prior Art
It is known to drill a hole in the earth with a rotating bit. In
such drilling, the bit may be loaded axially either by the weight
of the drill stem to which the bit is connected or by application
of fluid pressure to a piston or cylinder connected to the drill
stem anywhere along its length between the bit and the mouth of the
hole. The bit can be rotated by a motor connected to the drill stem
anywhere between its inner end adjacent the bit and its other or
outer end, which may be out of the hole at the earth's surface. It
is known to guide the bit to cause the hole to be bored in any
desired direction. For example, in U.S. Pat. Nos. 3,298,449 to
Bachman et al., 3,326,305 to Garrett et al. and 3,460,639 to
Garrett there is shown a bit deflection barrel around the drill
stem and through which the drill stem moves axially as drilling
proceeds, the drill stem being turned by an out of the hole motor.
U.S. Pat. No. 2,637,527 to Andrews shows a deflection and force
application barrel about a drill stem projectable into the hole as
drilling proceeds and carrying an in-hole motor between the barrel
and stem. It is also known to provide bit deflection means affixed
to the bit or to the drill stem adjacent the bit, such deflection
means moving axially in the hole as the bit proceeds. To take the
reaction force of an in-hole bit loading device, an in-hole motor
or a bit directing device, it is known to provide anchor means to
engage the wall of the hole being drilled. This is shown for
example in U.S. Pat. No. 556,718 to Semmer which also shows means
for advancing an in-hole motor and bit loading device along the
hole as it is drilled. Another example of such anchor means is the
construction shown in the U.S. Pat. No. 2,946,578 to DeSmaele. See
also U.S. Pat. to Kellner Nos. 3,088,532, 3,105,561, and to Kellner
et al U.S. Pat. Nos. 3,180,436, 3,180,437, and to Roberts U.S. Pat.
No. 3,225,844.
SUMMARY OF THE INVENTION
According to the invention, a deflection barrel is disposed about
the drill shaft, being free to turn thereabout to direct the motor
in the desired azimuthal direction. Hydraulic stepping motor and
vertical alignment means are provided for turning the barrel as
desired relative to the motor. A manifold is connected mechanically
to the outer end of the barrel providing means for connecting fluid
and electric conduits to the apparatus.
BRIEF DESCRIPTION OF THE DRAWINGS
For a further understanding of the nature and objects of the
present invention, reference should be had to the following
detailed description, taken in conjunction with the accompanying
drawings in which like parts are given like reference numerals and
wherein:
FIG. 1 is a schematic view of a motor with deflection apparatus
according to the invention together with associated bit and bit
loading apparatus;
FIGS. 1A through 5 together form a view partly in elevation and
partly in section and partly in phantom line showing an apparatus
embodying the invention;
FIGS. 6 through 16 are transverse and detail sections taken through
the apparatus shown in FIGS. 2A through 5 at the indicated planes;
and
FIG. 17 is a hydraulic circuit diagram for the position control
system forming part of the apparatus embodying the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1 there is shown a drill bit 21 connected to
sub 63 extending from shaft 23 of an in-hole motor 25 which in turn
is connected to an in-hole force applicator and counter rotation
anchor 27 supplied with fluid from conduit bundle 29. Similar
apparatus is already known, being disclosed in my U.S. Pat. No.
3,799,277 issued Mar. 26, 1974, entitled "Force Applicator," to
which reference is made for details of the construction thereof.
Briefly, motor 25 is of the fluid turbine type including shaft 23
and housing 31. Fluid for operating the motor and carrying away the
drill bit cuttings is supplied via sleeve 140 which forms the inner
end of tubular shaft 33, which also serves to transmit axial force
to the motor housing 31 and takes the reaction torque of the motor.
A continuation of shaft 33 provides a tubular mandrel or piston rod
35 which carries piston 37 moving in cylinder 39. Mandrel 35 and
cylinder 39 are provided with wall anchor means 41', 42 whereby,
with the cylinder anchor means actuated, the piston can apply axial
force to the motor through thrust ring 290', and with the mandrel
anchor means 41' actuated, force can be applied to the cylinder to
move it axially along the hole. The piston rod is connected to the
cylinder by spline means 44 which allows it to move axially while
the anchored cylinder prevents piston rod rotation so that the
piston rod can take the reaction torque of the in-hole motor
through Sprague or overriding clutch 278.
To direct the drill bit, a deflection barrel 41 is provided around
the motor shaft extension or sub 63, the barrel being provided with
asymetrically disposed wall engaging means 43 to urge the motor and
bit to one side of the hole. The wall engaging means 43 are adapted
to slide longitudinally along the hole as drilling proceeds. The
barrel is rotatable with barrel extension sleeve 53, shrink fitted
to motor housing 31, and housing extension 51, about the motor
shaft extension 63 to the desired position by means of a hydraulic
stepping motor 49 and its teeth means 153, 155, in cooperation with
sequencing clutch means 45. A mercury or other type potentiometer
55 as part of instrument package 34 transmits electric potentials
to an out of the hole Wheatstone bridge or other detector to
indicate the attitude of the hole, as shown in FIG. 16 of allowed
parent application, Ser. No. 584,736.
It will be understood that the invention is designed for use in
drilling a more or less horizontal hole or holes having at least a
horizontal component, so that the gravity actuated mercury
potentiometer provides an indication of the attitude of the hole
relative to a fixed frame of reference.
Referring now to FIGS. 1A through 3 there is shown (FIGS. 1A and
2A) a drill bit 21 having a pin 61 screwed into box 62 of sub 63.
Sub 63 has its outer end 64 (FIG. 2B) splined onto the inner end 65
of motor shaft 23 by male spline 66 on outer end 64 and female
spline 68 on end 65. Heavy radial and axial load ball bearings 67
(see also FIG. 2A and FIG. 6) lie between end 64 and cuff 69 which
is screwed to the inner end 71 of deflection barrel 41.
Rate of change control extensions 70 may be mounted on inner end 71
such as by welding to control the rate of change of direction of
the hole.
Barrel 41 is connected to shrunk fit motor housing 31. Cover 76 is
sealed to barrel 41 and motor 25 by annular elastomeric seal rings
73 disposed in annular grooves 75 in inner end 71 (FIG. 2A) and
cover 76 (FIG. 2B) respectively. Cover 76 is rotatably mounted on
sub 63 by heavy radial load roller bearings 78.
Referring also to FIGS. 1 and 7, two windows 77, 79 in the barrel
41 receive hole wall engaging blocks or pistons 81, 83 to form wall
engaging means 43. Between the pistons and the windows is disposed
elastomeric mounting means 86 for sealingly mounting the piston in
the windows and which allows the pistons to be moved outwardly by
pressure differential to engage the wall of hole 87 and which
retracts the pistons from wall engaging position, as shown.
Fluid for pushing pistons 81, 83 outwardly is conveyed between
elastomeric mounting means 86 and cover 76 through annular space
between barrel 41 and cover 76.
Annular channel 200 formed between cover 76 and outer end 94 of
barrel 41 is in fluid communication with annular space 93. It is
also in fluid communication with outlet 202 of a longitudinal
channel 204 formed between motor housing 31 and barrel 41. Channel
204 is in fluid communication with inlet 205 of channel 204. Inlet
205 is in fluid communication with annular space 231 sealed in
outer end 206 of motor housing 31 by seals 208, 210. Annular space
231 is in fluid flow communication with outlet 212 of variable size
orifice 211 and with inlet 235 of check valve 226, both mounted on
sleeve 140.
Variable size orifice 211 comprises outlet 212 and inlet 222 with
the passage 224 therebetween being restricted by valve element 220
mounted on threaded shaft 218 terminating in screw head 214.
Threaded shaft 218 is sized to threadingly engage threaded hole 216
provided to receive shaft 218 and valve element 220 and vary the
distance of insertion of valve element 220 within passage 224 to
regulate the flow therethrough.
Check valve 226 comprises inlet 235, outlet 233, and spring 228
holding ball 230 against shoulder 232. This permits flow only from
annular space 231 to valve inlet 235 to hydraulic fluid channel 98
via valve outlet 233.
Referring now to FIGS. 1, 2B, and 2C, secured about sleeve 140
between attachment sleeves 131 and 133, having seals 136 and 138
respectively, is instrument package 34 housed under threaded sleeve
148. As part of instrument package 34, there is included
potentiometer 55 or other attitude indicating device such as those
shown in the Composite Catalog of Oil Field Equipment And Services
published by World Oil, 31st revision, column 2, pages 2781-2788
manufactured by Humphrey, Inc. of San Diego, Calif.
The electrical conductors from such a device are fed through port
127 and extend along the length of sleeve 140 in cable 96 to an out
of the hole receiver-indicator via cable 259 (FIG. 1).
Referring now to FIGS. 2, 3 and 4, to turn the deflection barrel 41
to the desired position azimuthally about the inner end shaft 64,
sleeve 133 is connected to sleeve 151 of hydraulic stepping motor
49 in chamber 160. It is driven by fluids in conduit 98.
Chamber 160 is formed between sleeve 151 and sleeve 140 which is a
part of shaft 33. Piston sleeve 167 is threaded or otherwise
attached over split piston 165. Chamber 160 is sealed by piston
sleeve 167 sealingly engaged with sleeve 151 by seal 169 placed in
groove 171 of sleeve 167 and also sealingly engaged with sleeve 140
by seal 173 in groove 175 of piston sleeve 167. It is also sealed
by sleeve 133 sealingly engaged with sleeve 140 by seal 149 and
with sleeve 151 by seal 147. Orifice 183 provides fluid tight flow
communication between chamber 160 and tubular shaft or sleeve 140,
member 157 being axially movable on sleeve 140 and hence not in
fluid tight engagement therewith.
As part of hydraulic stepping motor 49, spring 159 is positioned in
chamber 160 and is held in compression between shoulder 161 of
piston follower sleeve 157 and shoulder 163 of piston 165.
Hydraulic stepping motor 49 includes teeth 153 milled into sleeve
133. Teeth 153 are positioned to engage with teeth 155 milled or
cut in piston sleeve 157. Spring 159 is of such strength as to hold
teeth 155 in engagement with teeth 153 as teeth 153 and sleeve 133
rotate and without relative movement of piston sleeve 157 with
respect to piston 165. Spring 177 is positioned in chamber 160 and
is held in compression between shoulder 179 of sleeve 133 and
shoulder 181 of piston sleeve 167. Alignment slot 187 is provided
in piston sleeve 157 with screw 189 passing through alignment slot
187 and engaging threaded opening 191 in enlarged portion 185 of
sleeve 140. Annular space 193 is formed between shoulder 197 of
piston sleeve 167 and shoulder 195 of outer end enlargement 190 of
piston sleeve 157.
The length of space 193 has a direct functional relationship to the
distance 228' between teeth 153 and teeth 155 and to the total
length of slot 187 so that when piston 165 is moved axially teeth
153 will mesh with teeth 155 thereby rotating sleeve 133 until the
points of teeth 155 come in contact with the valleys of teeth 153.
The length of slot 187 further permits shoulder 197 of piston
sleeve 167 to urge piston sleeve 157 to cam around screw 189 into
slot 228 while teeth 153 and 155 are engaged, further rotating
sleeve 133 thereby permitting teeth 155 upon disengagement from
teeth 153 to become positioned behind teeth 153 to again cause
rotation of sleeve 133 on the next engagement of teeth 153 with
teeth 155. Enlargement 190 is longitudinally abutted with
enlargement 192 of piston 165 at shoulder interface 194 prior to
each actuation of piston sleeve 167.
Referring now to FIGS. 4 and 5, to actuate piston 165, port 230' is
provided in sleeve 140 to permit fluid tight flow communication
between hydraulic fluid channel 98 and annular chamber 232' formed
by flange 234 of sleeve 151, sleeve 140, piston sleeve 167 and
piston 229 in cooperation with seals 173, 169 and 231.
Piston 229 is formed between sleeve 151 and sleeve 140 facing
oppositely to piston 165; with one driving surface 247 facing
chamber 232', previously described. Annular channel 236 is formed
between sleeve 151 and piston 229 to provide for drainage between
chamber 238, formed between sleeve 151 and piston extension 256,
and annular chamber 232'.
Piston 229 is provided with thin walled section 240 which in
cooperation with sleeve 140 and its upset section 244 forms annular
chamber 242 with driving surface 243 for piston 229. Port 246 is
provided in sleeve 140 to permit fluid communication between
annular chamber 242 and tubular shaft or sleeve 140. Chamber 242 is
made fluid tight by seals 231 and 248. Sleeve upset section 244
also slidingly supports thin walled section 240 and weight
attachment member 252. Weight 254 is provided as a part of weight
attachment member 252, said member being free to rotate about
sleeve upset section 244 by bearing connection 250 provided between
thin walled section 240 and attachment member 252.
Referring now to FIG. 5, to determine the current position of
pistons 81, 83 in order to orient pistons 81, 83 azimuthally with
respect to the axis of motor shaft 23, extension 256 is provided
for weight attachment member 252 terminating in finger 258 having
splines 260 thereon. Spline ring 262 is provided around split
sleeve 264 and is shrunk fit thereover to hold sleeve 264 to sleeve
244. Spline ring 262 prevents extension 256 from rotational motion
by engaging splines 266 on finger 258. Mandrel sleeve 264 does not
rotate during rotation of sleeve 151.
Sleeve extension member 268 is screwed into sleeve 151 and sealed
thereto with resilient O-ring 234'. Shoulder stop 266 is provided
on extension member 268 to prevent longitudinal motion of finger
258 beyond spline 262. Shoulder stop 266 is provided with slot 270
formed between bevel 272 leading to slot 270 on one side of slot
270 and with straight side 274 bordering slot 270 on the other
side. Slot 270 is of sufficient depth and width to permit the
insertion of finger 258 therein to permit the extension of splines
260 beyond engagement with spline 262.
Sprague clutch 278 is provided in annular opening (See FIG. 16)
with locking members 282 connected by spring band 280 to permit
rotation of sleeve 151 in only one direction relative to sleeve 140
(244), allowing azimuthal positioning of deflection barrel 141, but
preventing reactive rotation of motor housing 31 when motor 25 is
actuated to rotate bit 21.
Referring again to FIG. 5, a split thrust bearing ring 290' is
disposed in annular space 290. The inner periphery of the ring lies
in an annular groove in sleeve 264. The outer periphery of the ring
lies between the inner end of locking member 288 and a junk ring or
washer adjacent Sprague clutch 278. The thrust bearing ring
transmits axial force from upset section 244 of sleeve 140 to
extension member 268, the latter forming the outer end of motor
housing extension 51. By means of this thrust bearing ring, axial
force can be transmitted from the force applicator 27 (FIG. 1) to
the housing of motor 25, and through the thrust bearings in motor
25 and the outboard thrust bearings 67, 69 (FIG. 2A) to the bit,
21. The thrust bearing ring allows rotation of extension member 268
relative to upset section 244, so that deflection barrel 141 can be
azimuthally positioned relative to section 244 when desired,
although it will be recalled that Sprague clutch 278 limits such
rotation to one direction. Seals 284, 286 seal locking member 288
with rotation extension member 268 and with sleeve upset section
244 rotatable therewithin.
Referring now to FIG. 17, to operate the positioning mechanism,
hydraulic power pack 292 is provided in fluid tight flow
communication by hydraulic fluid pipe 294 to fluid volume indicator
296. Fluid volume indicator 296 is composed of cylinder 299 with
piston indicator 298. The position of piston indicator 298 is
representative of the volume of fluid presently contained in the
system supplied by hydraulic fluid line 98. As previously
discussed, hydraulic fluid line 98 may have only its initial or
line fluid in it, i.e., when pistons 81, 83 of wall engagement
means 43 are not extended and orientation is not occurring. This
would be indicated by piston indicator 298 in the "de-energized"
position 300. When the hydraulic stepping motor 49 and sequencing
clutch 45 are energized, but sequencing clutch 45 is not in its
extended pisition, "extended position" referring to extension of
finger 258 into slot 270, sufficient hydraulic fluid will be in the
system for indicator 298 to be in the "Stepping motor energized"
position 302. When finger 258 enters slot 270, sufficient hydraulic
fluid will have entered the system for indicator 298 to be in the
"Vertical signal" position 304. After sufficient time, when pistons
81, 83 of wall engagement means 43 have been extended by hydraulic
fluid flow through the time delay restriction valve 211 from line
98, and after proper orientation made by counting the steps from
"vertical," sufficient hydraulic fluid will have entered the system
for indicator 298 to be in the "Deflector engaged" position
306.
In operation of the apparatus, the motor 25 is actuated by power
fluid flowing through shaft 33, and piston rod 35 from hose bundle
29, to rotate bit 21. The bit is forced inwardly against the end of
the hole by the force applicator 27. At the same time, the wall
engagement means 43, including deflection barrel 41, may be
actuated to press the bit 21 laterally toward the opposite side of
the hole 87 (FIG. 2A) in a desired direction. Because limiters 70
are nonrotating, if the rate of change limiters 70 are forced
against the opposite side of hole 87, pressure may be let off
pistons 81, 83, to permit the limiters to lift off hole 87. If it
is desired only to drill straight ahead, the wall engagement means
43 will not be activated except as required to correct course. In
any case, as drilling proceeds, the wall engagement means 43 is
carried along in the hole with the in-hole motor 25. The drilling
apparatus may be removed periodically and the hole direction
surveyed or direction sensing apparatus may be incorporated in the
drilling apparatus to give a continuous indication of hole
direction. In either case, if a change of direction is desired, the
deflection barrel 41 is rotated to set it to press the bit 21 in
the desired direction and drilling continued with the wall
engagement means 43 active, its pistons 81, 83 being extended,
until the desired change in direction is achieved.
In order to rotate the deflection barrel 41 about the axis of motor
25, motor 25 is first stopped by stopping fluid flow through shaft
33. Hydraulic fluid pressure is then applied from hydraulic power
pack 292 to hydraulic fluid channel 98. The application of this
hydraulic fluid will have the effect of urging fluid into chamber
232' forcing piston sleeve 167 toward shoulder 179 and piston 229
toward shoulder 266. A small amount of fluid will also enter
restrictive orifice 211, but, because of the size of passage 224,
the amount of fluid will not be sufficient to actuate pistons 81,
83 of wall engagement means 43. The fluid will not build up but
will drain through check valve 226 when pressure is decreased in
hydraulic fluid channel 98.
As shoulder 197 approaches shoulder 195, the points of teeth 155
will engage the flanks of teeth 153 in cooperation with spring 159
and continue along the faces of teeth 153 to the valleys of teeth
153 thereby rotating connector 133 and all sleeves connected to it,
including barrel 41 and sleeve 151. When teeth 155 reach the valley
of teeth 153, screw 189 will have reached the slot 228 of hole 187
and shoulder 197 will have engaged shoulder 195. This will permit
piston sleeve 157 to rotate with connector 133 as screw 189 travels
up slot 228. When screw 189 has reached the end of the travel of
slot 228, fluid pressure is decreased from hydraulic power pack 292
to allow fluid drainage through check valve 226 and to permit
spring 177 to return piston sleeve 167 and piston 165 to their
original positions. This also causes a slight backward rotation of
piston sleeve 157 as screw 189 is traversed in reverse by slot 228.
The backward rotation of piston sleeve 157 will again position the
points of teeth 155 opposite the flank of teeth 153 for the next
engagement and rotation of the teeth. The stepping of hydraulic
motor 49 just described will be indicated by the fluctuation of
indicator 298 about demarcation 302 after initial longitudinal
travel from demarcation 300. The urging of piston 165 toward
shoulder 179 will cause drill motor driving fluid to be drained
through port 183 from chamber 160 and through port 246 from chamber
242 to sleeve 140.
Piston 229, having also been urged toward shoulder 266 by the
action of hydraulic fluid in chamber 232', will force finger 258 to
travel through chamber 238 and frictionally contact the end of
shoulder 266. Because splines 260 will be engaging spline ring 262
and bearing 250 permits relative rotation of piston 229 with weight
attachment member 252, finger 258 will not rotate even though
shoulder 266 will rotate with sleeve 268 as the hydraulic motor 49
is stepped. Therefore finger 258 will remain vertically aligned by
virtue of weight 254 and spline ring 262. By continuing to step
motor 49 however, eventually shoulder 266 will rotate to a position
where slot 270 will be opposite finger 258. At this position, the
hydraulic fluid acting through piston 229 will urge finger 258 into
slot 270 which will be indicated by the longitudinal movement of
indicator 298 to marking 304.
When finger 258 enters slot 270, slot 270 will have to be at the
top of the assembly because weight 254 in cooperation with thrust
bearing 250 and spline ring 262 has kept finger 258 at the top, as
previously discussed. Therefore, because the positional
relationship between slot 270 and pistons 81, 83 is known, the
positions of pistons 81, 83 are also known. When finger 258 enters
slot 270, weight attachment member 252 and weight 254 are free to
rotate with shoulder 266 using thrust bearings 250. Therefore
pistons 81, 83 may be positioned by continued use of hydraulic
stepping motor 49 with position indication given by the number of
steps of motor 49 using finger 258 engaged in slot 270 as a
starting reference.
When the pistons 81, 83 have been correctly positioned in hole 87
for proper deflection of bit 21, sustained hydraulic fluid pressure
can be maintained in hydraulic fluid channel 98 until sufficient
fluid has passed through restriction valve 211 to force pistons 81,
83 outward, engaging the hole which is indicated by indicator 298
moving longitudinally to position 306. Then, fluid may be
introduced through shaft 33 which will start drilling motor 25 and
also force piston 229 back to abutment with flange 234 by fluid
pressure through shaft 33 to orifice 246 to chamber 242 acting
against shoulder 243. This action will also disengage finger 258
from hole 270 and move splines 260 to their initial position
disengaged from spline ring 262. Check valve 226 is also used to
drain fluid from pistons 81, 83 when these are to be
contracted.
Although the system as described in detail supra has been found to
be most satisfactory and preferred, different applications and many
variations in its elements and the structure of its elements are
possible. For example, fluid can be introduced into port 183 from
sleeve 140 to return piston 165 and piston sleeve 167 instead of
using spring 177. Moreover instruments such as inclinometers,
accelerometers, and analyzers may be housed in instrument package
34.
The above are merely exemplary of the possible changes or
variations.
Because many varying and different embodiments may be made within
the scope of the inventive concept herein taught, and because many
modifications may be made in the embodiments herein detailed in
accordance with the descriptive requirements of the law, it is to
be understood that the details herein are to be interpreted as
illustrative and not in a limiting sense.
* * * * *